Thermal relay reset actuator



Sept 14, 1943 P. M. cHRlsTENsEN 2,329,252

THERMAL RELAY RESET ACTUATOR Original Filed Jan. 4, 1941 Inventar .Pau/M .Christ 5275527 l. my 1 'gymtarngf Patented Sept. 14, 1943 v Paul M. Christensen, Newington, Conn., assignor" to Colts Patent Fire Arms 'Manufacturing Connecticut Company, Hartford, Conn., a corporation oi Original application January 4, 1941, `Serial No.

373,189. Divided and thisv application Decembel' 24, 1941, Serial No. 424,325 g, A

s claims. (C1. v20opiaci This invention relates to improvements in thermal relay reset actuator mechanism for use in electric switches of the electro-magnetic motor starter type .and is a 'division of application Ser. No. 373,189, led January 4, 1941.

The above noted application is directed to improvements in a thermal rel-ay unit. The .thermal relay` reset actuator mechanism described in the instant applicationy is primarilyior use in con-. nection with resetting thermal relay units such as ,described in said application Ser. No. 373,189 but Vits use is not to be restricted only with lsuch units.=

In the latter application, the thermal relay unitdescribed therein is provided with movable, control means to make the relay either alitomatically or manually fresettable to .re-establish aninterrupted circui-t when normal current conditions again prevail in the circuit. Said circuit includes, inthe present illustration and description, a switch of theelectro-magnetic motor starter type. v

' The movable control means of the thermal relay unitdescribed in said application Ser. No. 373,189 alsoincludes a reset member comprising a movable control, plungerand. the prin-l cipal object of the present invention is to provide a simple and, effective actuator mechanism Cit.

forth in detail vby considering the following specilcation describing theaccompanying drawing,

` The accompanying .drawing shows the embodiment of the 4invention which is deemed preferablefbut it willbefun'derstood that the drawing is intended forjillust'rative purposes only and is Ynot to'be 'construed as dening or limiting the scope ofthe invention, the claims forming a part of this specicationbeing relied upon for that purpose. Y Y

In the drawing.;

Fig. 1 is a front elevational view of an electromagnetic .motor starter having two thermal relay units and a thermalj'relayreset actuating mechfor operatingthe, reset member on each of a plurality of thermal relayunitsin unison,` by simultaneously. engaging and moving each ofl saiciy reset members.

Another object .of the invention is to provide thermal relay reset actuator mechanism mounted entirely on a removable cover for a casing which houses theelectro-magnetic motor starter Whereby, when the cover is removed, the reset actuator mechanism is entirely removed therewith to leave the thermal relay units and their movable reset members comprising the movable control plungers fully exposed for manipulation, for example, to move said movable control plungers from automatically resettable to manually 'resettable position. l

A still further object of the invention is to provide a thermal relay 4reset actuator mechanism having resilient means whereby should one' or more movable control plungers fail to prop` erly move, no damage will be suiiered by the thermal relay unit or any of its component partsf anism, partlybroken away, mounted on the casing cover and the casing cover being partly broken away, and one of the thermal relays belng shown in section taken on the line l-l of Fig. 2. v

Fig. 2 is a sectional view taken on the line 2--2 ofFig. 1.

Fig. 3 is a sectional view taken on the line 3--3 of Fig. 1 with the casing cover and part of the thermal relay vreset actuator mechanism operatagainst Aclosing the circuit by the movable control means.

Fig. 7 is a view taken on the line l-l of Fig. 1 and showing the relay arranged to operate as automatically resettable. y

Fig. 8 is a sectional view taken on the line 8-8 of Fig. 5. l L l 1' Fig. 9 is a sectional view similar to Fig. 8 showing the parts in their relative positions of Fig. 6.

Fig. 10 is a detail view showing the switch operating link in plan and the switch lever in section on an enlarged scale.

Referring to thedrawing. and particularly to Figs. 1 and 2 thereof, the numeral IU designates av casing in which a unitary electro-magnetic motor starter and -thermal relays embodying the present invention is housed. The electro-magnetic motor Astarter and thermal relays are mounted on a base Il, and the base is secured to the bottomI of the casing I0 by suitable means such as screws l2, only one of which is shown in the drawing. The motor starter includes a stationary insulating contact base I3 which is shown fastened to the base I I by screws I4 which extend therethrough and engage in screw threaded openings in the base I I.

A frame I5 is stationarily mounted on the base Il by suitable means, not shown, in spaced relation to the stationary insulating contact base I3, and houses the electro-magnet of the motor starter.

is not shown or described l:inf detail in'ths .application since itis not a part of thepresentinvention. The electro-magnet is adapted to reciprocate an armature I8. To afford easy guided movement to the armature, itis suitably'attaehed to a carrier frame I9, which is not 'shown no'r described in detail in this application, but which is slidably supported in the frame I5. A movable insulating contact carrier 2q is lattached to the movable franie= I Sv Afor"recipro''ating' movement in the space between the,stationagcontactbase I3 and' @ne fixed `fram'e'or 'electrons-guet housing l5 -to bring contacts?! into bridging relation with respect Ato` contact'sZZ Von the `stationary insulating base I 3,' when the armature" I8' is attracted by 'the velectro,'-r1 iagnetjand 'causes ,frame I9 and carrier zato move.' Obviouslywhen the armature is released it drops and causes carrier Zjand contacts 2I to move away from contacts 22,

A push button control station conveniently .mounted on thetopfofgthe lectro-magnet housing wenn ingr-stangen@ jsto'pf push buttons erzpes'e'dg'ft en gh the cover'of' the casing for inan'ual"oi'jeratron'; and suitable connectionbinding 'posts' 24 arefprovided i'or,malsing desired circuit 'connections' f1; y j

'Figs l and 2 of the drawing show two thermal relays, designated. generally by the numeral 25, and embodying' the' present invention, vmounted on the base .II at opposite sides of the frai'noIS. Therelaysfare 'identical construction but .reversed as 'to positi'cn., Only one of the vrelays will be described, the"'reason for showing' two relays being to illustrate a complete actual magnetic r'riot'or 'starten'unit 'adaptedto control different circuits. Each' relay body 'or casing is shown as comprising a relatively thick part or'block 26 of molded insulating material,v and a plate 2710i ing 28 (Fig. 7) in the block. The opening 28 is located at the bottom of a recess 29 which receives a correspondingly shaped projection lor. the plate 2l' and through which the screw extends. Ech casing 25, with the mechanism of the thermal relay switch assembled thereon is positioned on the base 4II with the plate 21 against frame I5 of the magnetic motor starter and with openings 3D in alignment, with screw threaded openings in the sides of the frame I5. Screws 3i are'then inserted through the openings 35 and threaded 'into the openings in the frame I5 to hold the relays in their established places as part ol' the unitary structure of the magnetic motor starter.

The relay casing part 2G is substantially rectangular in form, and has an'outwardly extending projection 33 on its top. Two of the top corners, one at each side'of the projection 33, are cutaway to provide shoulders 34 for reception of stationary (electrical contact plates 35 and 36 The coil I5 of the electro-magnet is shown held against accidental-'movement -in .its housing I5 by aremovable yoke member Il, which which receive the binding posts 35' and 38' to electrically connect the relay swi 1h. hereinafter described, to the electro-magnet oi the nictcr starter. The arm of the Contact plate 35 which receives the binding post 35 overlies one of the shoulders 34, and the other arm of Contact plate is flatly disposed-against v"the'facc of the casing part 28 at one end thereof. The plate 38 is similarly mounted on the other shoulder 34, and will be hereinafter described more in detail --iii connection 'with the switch mechanism. When the pla-te 2l is attached to the part 26 the structure ofthe 'casing4 then provides recesses at the cut away corners and shoulders 34 in which the binding posts 35', 8G' are located (Fig. l). The relay casing p art 25 is open at its front, and a removable closure-'plate 31 forms, in conjunction with 'a transverse partition plate 36 and wells of the casing, a chamber to receive and l'iouse general, since various-'Wines of electric resistance units can be employed. -ln thedrawnggti'gs 2 and 8), the resistance unitcomprises 'plate 39 of insulating material Asupporting;afgriul 4Q, 'the terminals of which are 'loopedaround 'eyelets .4I- o'n the insulating plate 39, 'fTheplate'Bi overli'es and -covers a notch in the ,top o'ijthe' 'casing part 26 through which thegrid inse'rtible 'into and removable from -the ca-sing' 25. AThe eyeletsfl engage or rest on the topsof stationary electric' contact plates -42 which 'are sccuredtothe top ofthe casing by any suitable means., Screws' 43 engage threaded openingsiln the contact. plates 42 and the'heads of the I,screws 'engage the tops of the'eyelets 4I through which 'the screws eiztondA to 'detachably mount the 'electric'jresistnnce unitl in operating position in th'e relay casing. Binding posts 44 on the stationary Contact platt-s' 12 are provided for electrically connect-ing 'the'.r'e'- sista-nce unit in, electric c'ircuitswhiclit'he 'thermal relay and motor starter areto control,

AThe thermostatic element whieho'perates the switch hereinafter described. comprises" a bimetallic plate 45, one jend o'fyii-,fliifch isrig'idly secured to a bracket 46 in'anyfsiiitable manner. The bracket 46 is'substantia'lly 'LJ-shaped. and a screw 4'I is threaded'through openings in the arms of the bracket for Calibrating purposes in properly locating the bimetallic plate 45 relative to the grid 40-in itsoperative'position in casing 2'5. The bracket 4has -an'extf-:nsion 48 (Fig. 2) which receives screws 49 extending through the casing part 2'6 to rmly 4but detachably secure the bracket to the casing and maintain the bimetallic plate, in its normal condi-tion, in vproperly adjusted relation 'withrespect'to the grid 4U, so that the bimetalllo plate will be vdeflected to operate the switch, about atogbefdescribed, to interrupt the circuit when abnormal conditions therein cause the resistance unit 'to'be overhsfrtcd. Although the grid 4l) is shown iii-the' drawing as being positioned in front of the jbimetallic plate 45 in the said-casing ohambenthis arrangement canbe reversed, that is, .the bimetallic plate can be positionedin frontof thegridbecause the grid is removable from the top of the casing independenthf ofthe bimetallic plate. Of course, under such reversed arrangement thebmetallic plate would be secured tojlts supporting bracket with its other face confronting the grid to obtain deflection of the vplate in the vsaine direction 'as illustrated in the drawing top'roperly operatethe switch without changing or altering the structure Presently described.v I I :11;

The bimetallic plate 45 has a tongue=50 on its free end, and the tongue extends through a slot 5| in the reduced portion 52 ofjalslideor link. `in the nature of a strip'of insulatingmaterial, to detachably connect the bimetallicplate and slide. Obviously, movement of the'bimetallic plate dur. ing deflections under thermal conditions to which itis subjected in the relayncasngl willlimpart movements to the' slide or link.- Y:The .casing part 26 is provided with"channels 53' (Fig..f'l)y which receive the longitudinal edges .of'the lenlarged portion 54 of the slide or .link to support it rand guide it Aduring' its movements. TheA reduced -p'ortion 52 of the `slide or linkfexte'nds through aslot 55 (Fig. 2) 'in the partition plate 38 Yiti-casing part 26, and this arrangement also assists in' sup' porting and guiding the slide or link. Y It will be noted (Figs. f4.9);1thatal-cha1'riber 56 is provided in the'rear' 'of casing'l25'longitu-- dinally thereacross being formed by walls ofthe part 26, the partition plate 38. and the'casing plate 21, to house the'switch mechanism; and the enlarged portion 54 of the slide-is located transversely across the chamber 56 toactuatethe lever 51 of the quick action switch. The switch'lever 51 is preferably formed from a thin strip df-,metal the central area of which is struck-up to rigidity to `the'strin the struck-up area oi" hump being designated by the numeral 158.' Y' The 'pr'o-V visionI of the struck-up area'58 also stabilizes thelever during its workingir'ivements'he area 58 is located, as shown best in Fig.' i 10, through a slot 59 in the portion 54"of the s lide'j and the slot 59 has a straight side and a'conveXI side. The hump or struck-up area 58 engages 'the' convex side of the slot while the straight'por?A tions of the lever 51 at the sides and base of the struck-up portion 58 engage-the straight side of the slot, thus providing a three-pointmechankal4 contact between the slide and lever 51, which rocks relative tothe slideI during actuation there of. The lever 51 has a tongue BB extendingfroz'r'r one of its ends into an opening in the bottoml of the trough'of a substantially V-shaped saddle lil,l which is seated in a recess provided therefor in the wall of the casing part 26 at v'one end' of the chamber 56, serving toA fulcrumrsaid endhof the lever. 'I he other end of the lever 51 is notched for reception of one end of a substantially U- shaped over-center 'spring 64, thevother end of which is similarly arranged in the notched end of a movable electrical contact arm 65 tofme-f chanically connect the switch and vmovable elecl tric contact arm for'operation in a manner here-v inafter described in detail. The movable electric contact arm comprises a resilient strip of conducting material having one end secured to the casing part 25 withinfthe chamber 56 adjacent one end thereof by screws 66 which also engage with threaded openings 'in stationary contact plate 35 thus establishing elecf1 tncal connection between thel stationary contact plate 35 and movable contact arm 65. Thesta` tionary contact plate 36 at the other end of the casing 25 has an arm 61 arranged along a portion of chamber 56 in front of the switch, and an electric contact point 68 is secured to the inner face of the arm 61 adjacent its end. The mov; able contact arm has a similar contact point 69 secured to its outer face adjacent'its end whichv is connected tolthe over-center spring 64 andi'n'i" alignment with'contactpoint 68. The movable contactfarm j is biased to closedcircuit position, that 'is, to normally maintain the contact points 68;,and 69in engagement so that the relay will not interrupt the circuit in which it is connected so long as normalconditions exist in the circuit; butz. uponcreation of :abnormal conditions 'the thermostatic plater45 'will be deected by the grida40 `and move slide 54 which in turn moves lever 551 from: the Vposition ofi Fig. '.6 to the .,posi'- tion-.shown inFig.5.C."I.his causes shifting move# mentof the over-center spring`64 to move con; tact'arm 65 Aand the' contact'point Gather-con away from :contact point' 68, breaking thelcircuitl If there is nothing, .other than the abnormal cur-l rent conditionswhich yheatthe 'grid and 'cause dection of -the bimetallic plate which causes opening-of the circuit by operation of the switch as described, to `prevent closing movementf'l of biased-arml65 the 1 movable contact will auto# maticallylbe'returned to closed circuit position when normal condition in -the `circuit again pre'-`` vailsand permits cooling of the bimetallic ele ment and return to its original position, as should be obvious. However, there are conditions under which it is-desirable to maintain the switch 'and movable electricl contact yarm from@re-establish'-v ing or closing; the circuit automatically, and mak-v ing it necessaryito eiect reclosing ofy thecir'cuit by hand operation, and thev present invention provides means for 'making the 'relay either `auto feature will now-be described;- A

The casing parts" 26 and21' have complemental faces 'which intert Atoform a housing for the stationary conta-ct Vplates- 35 and 36, movable contact'arm-"65,'.the'reset member comprising the 'movabley control plunger 10, and the associated parts on Ithe reset member.

.maticallyior hand-vresettable as desired, which plunger.

The'v movable contact arm 65, a thin resilient strip of Imetal, previously described in part, has a curved substantially -llshaped-portion'1l inter-1i mediate its ends arranged in alignment with the control plunger 10, the saidl U-shaped portion l1|I to accommodate vandcOOper'ate with the plungerl aswill be pointed out in detail hereinafter. The complemental faces of the casing parts 26 and 21 each have corresponding grooves 12 formed therein adjacent their top's to form a chamber 13 when assembled. A coil spring 'M is mounted on the stem of the controlplunger 10 and partly compressed between a fixed collar 15 on the control plunger stem and the bottom of chamber 13 to pressA against the collar rand urge the plunger outward. A head 16 is provided on the' outer end of the control plunger stem for engagement by a nger of the handv when turning the control plunger to establish it in operativev and inoperative positions whenv making the relay either manually or automatically resettable.

' The thermal relay reset actuator mechanism forv manually resetting the relays comprises a reset button 11 conveniently provided on the cover I0 on the casing I0 adjacent the push button control station 23 and a spring plate l18L rigidly connected at 0r near its bottom edge to the inner face of the front cover Illa. The plate extends upwardly from its points of attachment to the cover and has a medial portion or section span' ning the V'lower portion of the switch. The front face of said medial section is in position to be engaged by the rear end of the button 11 as clearly shown in Figs. 2' and 3. The spring plate 'l1a is generally crescent-shaped with the ends forming The control plunger- 10 may also be designated a movable reset control 'circietepiatt be'acepmpiisileainntu nien-tunel plunges wie ufficientity3 depressed mfariiiauyfey prssureenfits; heeel-1s tirvithuue'ezlbevnq thel eieffirislipecilpcne a ejer fthefnrovabi cdntaetfniwrg tblefniittnannsnigvrvea by .i991 thermal .relay swiieliimhislf'if'ihe positiono'ffii-g-'B ibiiously, when downward pressure on the control plunger is released the spring 14 urges it upward and it is arrested in its upward movement by engagement of the shoulder of lug 82 against the confronting edge of the movable contact arm portion 1I.

Opening or rearward movement of the movable contact arm 65 is limited by stops or lugs 83 located in the chamber 56 of the casing 25 behind said arm, and by similar lugs 84 in the chamber behind the switch lever 51 for abutment thereby. Closing or forward movement of the same parts is limited by -engagement of contact points 68 and 68.

It should be apparent from the foregoing that in order to make the relay automatically resettable the control plunger 'l0 is depressed as far as it can move downward against spring 14 and given a quarter turn to place the lug 82 in locked relation with the lugs 8| in chamber 80 so that only the stem of the control plunger extends across the U-shaped portion 'H of movable contact arm 65 and spring 14 is inactive. The stem of control plunger 10 is then disposed across U-shaped portion 'H but suiciently clear or spaced therefrom to not interfere with operation of the contact arm 85 in either direction of its circuit making and breaking movements. To make the relay manually resettable the control plunger is given a quarter turn inv reverse direction to establish the lug 82 in operative relation with the movable contact arm 65 as previously explained. The head 'I6 of the control plunger is pointed at one end to conveniently serve as an indicator as to which of its selective positions,A

operative or inoperative, the control plunger occupies, so that the operator will readily know whether the relay is manually or automatically resettable.

While the thermal relay reset actuator mechanism has been herein described in connection with thermal relay units forming the subject matter of said above mentioned application Ser. No. 373,189, it is to be distinctly understood that said thermal reset actuator mechanism is applicable to any other types of structures with which its use is suitable.

The invention has been illustrated and described'in its preferred embodiment and has included certain details but, it should be understood that the invention is not to be limited to the precise details herein illustrated and described since the same may be carried out in other ways, falling within the scope of the invention as claimed.

What I claim is:

l. In combination with an electric switch oi the magnetic motor starter type, a casing, a plurality of thermal relay units mounted in said casing and each having a movable reset control member, a movable cover mounted on said casing, a member mounted on and entirely carried by said cover, said member having resilient means thereon adapted to be moved with respect to said cover into substantially simultaneous engagement with said reset control members, and means to urge said member into substantially simultaneous resilient engagement with said reset control members.

-l 1 2.' :'In x'consibination iwi'thf an 'electric'.- switch vl`of the magneticlmotor starte'r type; 'a'casing Ja plu'- rality o'tthe'rmal relay units mounted in v'said `'casing- Land-f1 eacl'r having I a movable reset =contro1 membrgifmovable' cover? mounted. on. 'said' casing; 'iai resilient mer'nberi entirely carried r by said boven-'fand mountedithereonwithlone .en'df .movable with respect thereto, said resilient member being adapted to resiliently engage Said reset control members substantially simultaneously upon actuation of the movable end of said resilient member, and means to urge said resilient member into substantially simultaneous engagement with said reset control members.

3. In combination with an electric switch of the magnetic motor starter type, a casing, a plurality of thermal relay units mounted in said casing and each having a movable reset control member, a movable cover mounted on said casing, and a resilient member entirely carried by said cover and having one end iixed thereto with the remainder of said member movable with respect thereto and having a portion terminating in a pair 9i spaced sections each having gradually diminishing widths toward its outer end which forms an arm adapted to resiliently engage one of said reset control members whereby upon actuation of said resilient member the reset control members of said plurality of thermal relay units are substantially simultaneously engaged and moved to reset position.

4. In combination with an electric switch of the magnetic motor starter type, a casing enclosing said switch, a plurality of thermal relay units mounted in said casing and disposed at opposite sides of said switch, said thermal relay units each having a movable reset control member, a movable cover mounted on said casing, and a resilient member entirely carried by said cover and j' mounted thereon with one end movable with re' .f spect thereto, said resilient member having a medial section spanning a portion of said switch' and the movable end thereof having a plurality of spaced projecting arms each being adapted to resiliently engage one of said reset control members whereby upon actuation of the movable end of said resilient member the reset control members of said plurality, of thermal relay units are substantially simultaneously engaged and moved to reset position.

5. In an electric switch construction of the magnetic motor starter type the combination of a casing for said switch, a movable cover mounted on said casing, a thermal relay unit mounted in said casing and including a reset control member adapted to be manipulated manually to move the same to one position to render the thermal relay unit automatically resettable and to another position to render the thermal relay unit manually resettable, and a reset control member operating means adapted to move said reset control member when the same is in manually resettable position to reset said thermal relay unit, said operating means being entirely carried by said movable cover whereby when the latter is moved away from said casing the reset control member is rendered readily accessible for manual manipulation.

6. In an electric switch construction of the magnetic motor starter type the combination of a casing for said switch, a movable cover mounted on said casing, a plurality of thermal relay units mounted in said casing and each including a reset control member adapted to be individually manipulated manually to move the same to one position tov render .the thermal: relay unit automatically 'resettable Iand, tto another position yto render the thermal relay unit manually. resettable, and a reset .control member., operating means adapted -to L substantially simultaneously move said reset control members whenzthesame are inl manually resettable. position Lto reset -said plurality of ytriennal;relayl units, said operating means being Lentix'e-1ygcarxledjnyfy saidmovable cove;` fwhereby when the latte;` is moved :away fromtsaid casing said resetcontrol members are rendered rreadily accessible iorsaid; individual manualfmanipulation f f I Y ,q-PAULM CHRISTENSEN- CERIIF ICATE OF CORRECTION Patent No. 2,529,252. september 1li, 19M.

PAUL M. CHRISTENSEN.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 2, first column, v line E2, for "station 2 read `station 25; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 26th day of October, A. D. l9li5.

Henry Van Aredale (Seal) Acting Commissioner of Patents.

CERTIFICATE OF CORRECTION'.

Patent No. 2,529,252. september 1u, 1915.

PAUL M. CHRISTENSEN.

It is hereby certified that error appears in the printed specification of; the above numbered patent requiring correction as follows; Page 2, first column, line 52, for "station 2 read -'station 25"; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Office.

signed and Sealed this 26th day of october, A. D. 1915.

Henry Van Arsdale,

(Seal) Acting commi ssoner of Patents. 

